powerpc/kuap: Add a generic intermediate layer

Make the following functions generic to all platforms.
- bad_kuap_fault()
- kuap_assert_locked()
- kuap_save_and_lock() (PPC32 only)
- kuap_kernel_restore()
- kuap_get_and_assert_locked()

And for all platforms except book3s/64
- allow_user_access()
- prevent_user_access()
- prevent_user_access_return()
- restore_user_access()

Prepend __ in front of the name of platform specific ones.

For now the generic just calls the platform specific, but
next patch will move redundant parts of specific functions
into the generic one.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eaef143a8dae7288cd34565ffa7b49c16aee1ec3.1634627931.git.christophe.leroy@csgroup.eu

1 files changed, 4 insertions, 6 deletions

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 170339969b7c..03d61c5205a4 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -268,8 +268,7 @@ static inline void kuap_user_restore(struct pt_regs *regs)
 	 */
 }
 
-static inline void kuap_kernel_restore(struct pt_regs *regs,
-					   unsigned long amr)
+static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
 {
 	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
 		if (unlikely(regs->amr != amr)) {
@@ -287,7 +286,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs,
 	 */
 }
 
-static inline unsigned long kuap_get_and_assert_locked(void)
+static inline unsigned long __kuap_get_and_assert_locked(void)
 {
 	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
 		unsigned long amr = mfspr(SPRN_AMR);
@@ -298,7 +297,7 @@ static inline unsigned long kuap_get_and_assert_locked(void)
 	return 0;
 }
 
-static inline void kuap_assert_locked(void)
+static inline void __kuap_assert_locked(void)
 {
 	if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
 		WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
@@ -339,8 +338,7 @@ static inline void set_kuap(unsigned long value)
 	isync();
 }
 
-static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
-				  bool is_write)
+static inline bool __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 {
 	if (!mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
 		return false;